A principle function of absorbent articles, such as infant diapers and adult incontinent briefs, is to absorb and contain body waste. Such articles are designed to prevent body waste from soiling, wetting, or otherwise contaminating clothing or other articles, such as bedding, that come in contact with the wearer. A common mode of failure for such products occurs when body waste leaks out of the gaps between the article and wearer's waist to adjacent clothing due to the fact that it is not immediately absorbed within the article. This is most evident with loose fecal material that is not easily absorbed by the absorbent article.
Fecal waste, even in liquid form, usually has a higher viscosity versus urine and contains a certain degree of solids. The solids tend to block the small pores of the nonwoven coverstock and reduce penetration to the absorbent core underneath. In addition, the absorbent core is mainly designed to absorb urine and not solids. As a result, fecal material tends to "remain" on top of the coverstock. When the article is in a horizontal position, as in the case of the subject lying in a prone position, the combination of bodily pressure on the article and geometric position may force it out of the article, primarily out through the back waist region.
Infant diapers and adult incontinent briefs have significantly improved in the property of bodily waste containment; however, most developments have been in the area of urine containment. Liquid or solid fecal waste leakage is still a significant problem to the consumer. This type of messy leakage is more of a problem to the consumer than urine leakage. In most cases, more work and time is needed to soak, wash and clean soiled clothing as a result of fecal waste leakage. A significant improvement in this area would be greatly valued by the consumer.
Various disposable absorbent articles exist today for absorbing waste material of infants and adults. One of these is a disposable diaper that is fitted on the baby by the mother or caretaker. How tightly the diaper is wrapped around the baby's waist depends on the mother or caretaker. However, no matter how tight the mother or caretaker may attach the diaper on the infant, a perfect seal is not formed at the back waist area of the diaper to prevent fecal waste from leaking out. This is especially so if the infant is laying on his/her backside and the fecal waste that is emitted is fluid in nature and significant in volume.
Other waist barrier features have been identified for disposable diapers, such as elastic waistcaps for reducing the leakage of body exudates from the diaper waist region. Examples of such diapers are disclosed in U.S. Pat. No. 4,738,677 (Foreman) and U.S. Pat. No. 5,026,364 (Robertson).
Disposable diapers containing pockets or waist flaps are disclosed in U.S. Pat. No. 4,753,646 (Enloe), U.S. Pat. No. 5,304,160 (Igaue et al.), and U.S. Pat. No. 5,601,543 (Drier et al.).
The concept of utilizing waist elastic to contain bowel movement is disclosed in U.S. Pat. No. 5,151,092 (Buell et al.), and U.S. Pat. No. 5,700,255 (Curro et al.).
The use of additional absorbent material at the waist area of disposable absorbent articles is disclosed in U.S. Pat. No. 5,601,545 (Glaug et al.).
The use of adhesives that attached to the body in sanitary napkin designs are disclosed in U.S. Pat. No. 5,445,627 (Mizutani et al.), U.S. Pat. No. 4,753,648 (Jackson), U.S. Pat. No. 2,742,903 (Lightner), and International Publication No. WO 97/28773, issued Aug. 14, 1997.
U.S. Pat. No. 4,627,847 (Puletti et al.) discloses a hot melt adhesive waste barrier, and U.S. Pat. No. 2,512,713 (Cahill) discloses a rectal bandage.
While the prior art disposable absorbent articles may be generally suitable for their various intended purposes, there still exists a need for a disposable absorbent article, e.g., an infant diaper, adult incontinent brief or shield, etc., that is both effective and efficient in containing fecal waste (primarily in liquid form) from leaking out the waist opening of the article. In this regard, prior art disposable articles focus on either improving the elastic gathering at the waist area (waistband) or adding a pocket (waist flap) with elastic means to contain fecal waste, neither of which has solved the problem of liquid fecal leakage sufficiently well. In this regard, the prior art elastic waistbands have not eliminated or significantly reduced liquid fecal waste leakage for several reasons. In particular, elastic tension at the waist cannot be tightened high enough to eliminate leakage (too high elastic tension will cause significant discomfort to the user and red marking/irritation to the body). Also, elastic memory will reduce over time, especially under high stress conditions (loss in elastic memory will allow gaps to form in which fluid or liquid mass can leak out). Further still, elastic gathering of materials creates corrugations within the material that could allow fluid or liquid mass to pass through the small openings and cracks.
The addition of pockets or waist flaps have not eliminated or significantly reduced liquid fecal waste leakage for disposable absorbent articles either. In particular, these pockets may catch a portion of the fecal waste that is expelled, however the majority of it bypasses this type of barrier system. This is especially true if the fecal waste is in liquid form, is under high pressure or stress (e.g., the absorbent article is squeezed against the body), is significant in volume and is rapidly expelled or ejected from the body.
Accordingly, a need still exists for a disposable absorbent article which is resistant to leakage of liquid or loose fecal matter at the waist area.